Axpo is renewing and modernizing the facilities of the supra-regional distribution grid at the Wildegg-Brugg power plant in Villnachern.
As part of this, Axpo is replacing the existing switchgear due to its age. Construction work will start in spring 2025, and Axpo will further strengthen the security of supply in the region with this modernization.
Supra-regional distribution grid
The existing switchgear, which is housed in the Willdegg-Brugg power plant (KWWB), has reached the end of its technical life. Axpo is also increasing the voltage of its supra-regional distribution grid from 50 to 110 kilovolts (kV). For these reasons, the 50 kV air-insulated indoor switchgear will be replaced by a modern and compact 110 kV switchgear. The switchgear will be used to connect and disconnect the connected lines (Umiken, Wildegg and Lupfig) of the supra-regional distribution grid and the KWWB.
For operational and technical reasons, the new switchgear will be housed in a new building next to the wastewater treatment plant (WWTP) in Villnachern in the zone for public buildings. The substation will be built on land owned by the municipality of Villnachern, for which the municipality has granted Axpo a building lease.
Optimizing visual integration
The Swiss Federal Inspectorate for Heavy Current Installations (ESTI) approved the construction in August 2024
The Swiss Federal Inspectorate for Heavy Current Installations (ESTI) approved the construction in August 2024. Due to conditions relating to vegetation and soil moisture, it is not possible to start construction in autumn/winter. Construction work is therefore scheduled to begin in spring 2025. The new substation is scheduled to be commissioned in 2026.
The building was designed in consultation with the municipality of Villnachern and Pro Natura in order to optimize its visual integration into the landscape. It will consist largely of wooden elements. The site will also be enhanced with ecological infrastructure. Once built, the facility will not generate any additional emissions such as noise or traffic. It will be operated and monitored remotely.
Increasing transmission capacity
Axpo is gradually increasing the operating voltage of its supra-regional distribution grid from 50 to 110 kV in order to adapt it to future requirements.
The voltage conversion will increase the transmission capacity of the grid and reduce grid losses by 75 per cent. The operating voltage of the grid in the Unteres Aaretal/Brugg region is also being converted. An important part of this is the renewal of the Villnachern substation.
